This document provides teaching materials for an English second grade lesson on modals of deduction for past tense. It discusses using modal verbs like "might have" and "must have" to make guesses about the past. As an example, it analyzes past deductions about Stonehenge and the Egyptian pyramids. The lesson also includes a reading about the ancient Anasazi civilization that lived in Mesa Verde, Colorado between 1200-1300 AD, leaving clues but no records of why they abandoned the area. Homework includes exercises practicing these past modal verbs based on the Mesa Verde text and pictures.

1. English, Second Grade
Teaching Unit 1 – Lesson 10 MYSTERIOUS PLACES
GRAMMAR
Modals of deduction (past)
 We have already talked about making guesses about the present. In that case we use modals (must,
can’t, could, might) + infinitive.
E.g. Some people say there must be a creature in the lake.
Others say there can’t be.
They could be looking for her with the wrong equipment.
The monster might live under the ground somewhere in the loch.
 This time we are going to talk about making guesses about the past. In this case we use modals +
perfect infinitive (have + past participle).
E.g. Stonehenge might have been a place for observing the stars and planets.
- It is possible that this was the case in the past.
It can’t have been easy to pull the stones at Stonehenge upright.
- We are sure this was not the case in the past.
It must have been enormously difficult to build the pyramids/
- We are sure this was the case in the past.
HOMEWORK: Do exercise 2 d p. 75.
 Now, something different. Look at the picture on page 75.
What can you see?
Try to guess the answers to questions under 4 a p. 75.
 Here is an interview with a historian.
Mesa Verde is a part of the a national park, which is also called Mesa Verde, and it’s in the state
of Colorado in the United States.
Mesa Verde is basically a collection of housesand otherbuildingsthat were built in caves or in
other parts of a rock wall by a tribe of people called the Anasazi.
The name Anasazi means‘the ancient ones’ in the Navajo language.The Mesa Verde houses were
built in around 1200 AD – that is, just over eight hundred years ago. The Anasazi lived in these
rock and cave houses for about a hundred years.
The Anasazi built housesin the rock because it’s probable that living in the rock made themfeel
safer. But, it’s clear that by 1300 the buildings at Mesa Verde were empty.
The Anasazi left because they could have been afraid of another tribe. Or they might have had
problems with food – their population grew and they didn’t have enough food for everyone.
When the Spanish were in this part of the world, in around 1760, and when they were travelling
acrossthe country to California,theywentpasthere andgavethe place itsname – itliterally means
‘green table’ or ‘green tableland’, in Spanish.
The Spanish can’t have seen the buildings because they didn’t record them at all.
It was only around the last part of the nineteenth century that people began to uncover all these
wonderfulbuildings.Itbecame a nationalpark in 1906– butalreadya lotof thingshadbeenstolen
frominside the houses. Thieves must have stolen so many wonderful things – but at least it’s a park
now and nothing more is being taken away from the place.
The houses themselves are quite incredible – one famous one has 94 rooms and we reckon that
about 100 people lived in it at one time.
HOMEWORK: Read the text and check your ideas in 4 a p. 75, then complete the notes in 4 c p. 75.